2nd-closest black hole to Earth discovered

JERUSALEM — An international team of astronomers found the second-closest known black hole to Earth, the European Space Agency, or ESA, and Israel's Tel Aviv University said in separate statements on Thursday.

The newly discovered black hole"Gaia BH2" is located about 3,800 light-years from Earth and about 10 times more massive than the sun.

The closest known black hole Gaia BH1, which was also discovered recently, is about 1,560 light-years from Earth.

The team, which included researchers from the United States, Israel, Germany and Denmark, studied the orbits of stars tracked by the ESA's Gaia space telescope, which was launched into space in 2013.

The team noticed that some of the stars wobbled in the sky, indicating that they are gravitationally influenced by massive objects.

"The accuracy of Gaia's data was essential for this discovery. The black holes were found by spotting the tiny wobble of its companion star while orbiting around it," said Timo Prusti, ESA's Gaia project scientist.

Several telescopes looked for the objects, but no light could be found, which left only the possibility of a black hole.

A black hole is a celestial object with such a strong gravitational field that no object or radiation close to it can escape, but be swallowed into it.

The ESA noted that until recently, all the black holes astronomers knew of were discovered by emission of light produced by materials falling in.

The new black holes, on the other hand, are truly black and could only be detected by their gravitational effects on their companion stars, the ESA said.

Agencies - Xinhua